If you want an idea of how dishonest the Capital Weather Gang’s claims are, check out these numbers. Lincoln, Virginia has had 1281 days since 1901 over 95 degrees. 87% of those hot days occurred when CO2 was below 350 ppm CO2. There is no connection between heatwaves in DC and CO2 – and anyone who claims there is, is either an idiot or a liar.

The 1930s saw 268 days over 95F, or an average of twenty-seven days per year.

By contrast, the decade from 2000 to 2009 saw only 43 days over 95 degrees, or an average of four days per year.

The current decade has averaged twelve days per year over 95F.

Very hot days were three to seven times more common during the 1930s, than they have been since the year 2000.

19 Responses to DC Was Much Hotter During The 1930s

Well I guess that if DC was hotter than it must really mean that we are on the brink of a new ice age. Or whatever.
Anyone who can’t see that the world is getting warmer but take their head out of their butt

Why didn’t we have global warming in 1910 or 1930 when DC had most of their hottest temps.? Was CO2 higher back then? OR are the models wrong? The last 15 years have been flat but the CO2 has been increasing?? I do not understand

It isn’t very far, but it is the closest USHCN station to DC which has contiguous records going back to the 1930s. That makes it the best option for this comparison. You are raising a straw man and I have extremely little patience for people who do that.

Do you think that temperature trends in DC are very different from 25 miles away? That is just plain daft.

I’m not raising a “straw man.” The point is important. First, Lincoln is about 50 miles from Washington (http://www.distancebetweencities.net/lincoln_va_and_washington_dc/).Second, Lincoln is subject to much more impact from downsloping than Washington is. Third, in its benchmark 1930s summer (Summer of 1930), Washington, D.C. didn’t have 27 95° days; it had 26.

Yesterday, I rode by the asphalt jungle known as Reagan National Airport around 3 PM. The reading on my car thermometer was 12 degrees warmer than when I left my home in College Park, MD, about 10 miles away. No one can convince me that National is representative of the DC area. So yes, comparing Lincoln to Lincoln seems far more valid than getting involved with that obvious heat island around National Airport.

Lincoln, VA is much more subject to downsloping than DC? How does that manifest itself? Both places are east of the same mountains. Once the air downslopes, it downslopes. It doesn’t downslope in reverse going a few extra miles to the east.

The impact of downsloping is greater at Lincoln than at Washington, D.C., as Lincoln is closer to the mountains. As air descends and encounters higher pressure, it warms. Once that mechanism (of sinking air encountering ever higher pressure) is gone, the adiabatic heating ends. In general, the farther away from the maximum point of adiabatic heating the air moves, the more it can be moderated by the environment over which it passes. As Lincoln is closer to the area of maximum adiabatic heating, it is impacted more by the downsloping than Washington, D.C. The extreme numbers from the 1930s vs. those from Washington, D.C. (its station at the time was downtown).